Plant oil emulsion modifies internal atmosphere, delays fruit ripening, and inhibits internal browning in Chinese pears
Zhiqiang Ju, Yousheng Duan and Zhiguo Ju
Postharvest Biology and Technology Vol: 20 Issue: 3 Pages: 243-250.
2000
บทคัดย่อ
'Laiyang Chili' and `Ya Li' (Pyrus bertschneideri Reld) pears
were treated with 3, 6, and 9% emulsions of commercial or refined (reduced -tocopherol
levels) plant (soybean, corn, peanut, linseed, and cottonseed) oils at harvest
an stored at 0°C for 6 months. Effects of oil treatments on ethylene
production, respiration, fruit firmness, fruit color, soluble solid content
(SSC), titratable acids (TA), internal browning (IB), and internal CO2,
O2, and ethanol were studied. At the same concentration, oil
treatments induced similar responses regardless of their sources or their
-tocopherol
concentrations. In both cultivars, ethylene production and respiration in fruit
treated with 9% oils were lower in early storage and higher in late storage
than that in the controls. Oils at 6% reduced IB, at 9% inhibited IB
completely, and at 3% was not effective after 6 months at 0°C and 7 days at
20°C. Plant oil treatment maintained fruit color, firmness, SSC, and TA in a
concentration-dependent manner during storage. In the first 4 months storage,
9% corn oil-treated fruit contained similar partial pressure of CO2
and O2 as the controls. After 5 months storage, oil-treated fruit
contained higher partial pressure of CO2 and lower levels of O2
than the controls. When held at 20°C for 7 days, changes of internal CO2
and O2 were slower but partial pressure of CO2 were
higher, and O2 were lower, in 9% corn oil-treated fruit than in the
controls. Internal ethanol was not affected by oil treatment compared with
control, either during storage or 7 days at 20°C. No off-flavor was detected in
either oil-treated and control fruit by sensory evaluation.